Multi-beam inspection device

Abstract

A multi-beam inspection apparatus including an improved source conversion unit is disclosed. The improved source conversion unit may include a microstructure deflector array that includes a plurality of multi-pole structures. A deflector array of microdeflectors may include a first multipole structure having a first radial offset from an array center axis and a second multipole structure having a second radial offset from the array center axis. The first radial offset is greater than the second radial offset, and the first multipole structure includes a greater number of electrode electrodes than the second multipole structure to reduce deflection aberrations when the plurality of multipole structures deflect the plurality of charged particle beams.

Description

[0001] Description of the case

[0002] This application is a divisional application of the Chinese invention patent application with application number 201980087246.8 and name “Multi-beam inspection device” filed on November 26, 2019.

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS

[0004] This application claims priority to U.S. Application No. 62 / 787,157, filed December 31, 2018, which is incorporated herein by reference in its entirety. Technical Field

[0005] Embodiments provided herein relate generally to a multi-beam inspection apparatus, and more particularly to a multi-beam inspection apparatus including an improved source conversion unit. Background Art

[0006] When manufacturing semiconductor integrated circuit (IC) chips, pattern defects or foreign particles (residues) will inevitably appear on the wafer or mask during the manufacturing process, thereby reducing the yield. For example, foreign particles may cause trouble for patterns with smaller critical feature sizes, which have been adopted to meet the increasingly advanced performance requirements of IC chips.

[0007] Pattern inspection tools with charged particle beams have been used to detect defects or foreign particles. These tools typically use a scanning electron microscope (SEM). In an SEM, a primary electron beam with relatively high energy is decelerated, falls on a sample with a relatively low landing energy and is focused to form a detection point thereon. Due to this focused detection point of the primary electrons, secondary electrons will be generated from the surface. Secondary electrons may include backscattered electrons, secondary electrons, or Auger electrons generated by the interaction of the primary electrons with the sample. By scanning the detection points on the sample surface and collecting the secondary electrons, the pattern inspection tool can obtain an image of the sample surface. Summary of the invention

[0008] Embodiments provided herein disclose a particle beam inspection apparatus, and more particularly disclose an inspection apparatus using a plurality of charged particle beams.

[0009] In some embodiments, a microstructure deflector array in an inspection device includes a plurality of multipole structures, each of which includes a plurality of pole electrodes. The microdeflector array includes: a first multipole structure among the plurality of multipole structures, the first multipole structure having a first radial offset from a central axis of the array; and a second multipole structure among the plurality of multipole structures, the second multipole structure having a second radial offset from a central axis of the array. The first radial offset is greater than the second radial offset. In addition, the first multipole structure includes a greater number of pole electrodes than the second multipole structure to reduce deflection aberrations when the plurality of multipole structures deflect a plurality of charged particle beams.

[0010] In some embodiments, the microstructure deflector array may include one or more layers of multipole structures. The first layer of multiple multipole structures includes a first multipole structure having a first radial offset from the center axis of the array and a second multipole structure having a second radial offset from the center axis of the array. The first radial offset is greater than the second radial offset. In addition, the first multipole structure includes a greater number of pole electrodes than the second multipole structure to reduce the deflection aberration of the corresponding charged particle beam. The microstructure deflector array also includes a second multipole structure layer of multiple multipole structures, and the second multipole structure layer includes a third multipole structure having a third radial offset from the center axis of the array.

[0011] In some embodiments, a method of manufacturing a microstructure deflector array is provided. The microstructure deflector array includes a plurality of multipole structures and each multipole structure includes a plurality of polar electrodes. The method includes forming a first multipole structure to have a first radial offset from a central axis of the array. The method also includes forming a second multipole structure to have a second radial offset from a central axis of the array, wherein the first radial offset is greater than the second radial offset and the first multipole structure has a different number of polar electrodes than the second multipole structure.

[0012] Other advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings in which are set forth, by way of illustration and example, certain embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other aspects of the present disclosure will become more apparent through the description of exemplary embodiments with reference to the attached drawings.

[0014] Figure 1 is a schematic diagram illustrating an exemplary charged particle beam inspection system consistent with embodiments of the present disclosure.

[0015] Figure 2 It is a diagram showing an embodiment consistent with the present disclosure. Figure 1 Schematic diagram of an exemplary multi-beam apparatus that is a portion of an exemplary charged particle beam inspection system.

[0016] Figure 3Ais a schematic diagram of an exemplary multi-beam device consistent with an embodiment of the present disclosure, illustrating Figure 1 An exemplary configuration of a source conversion unit of an exemplary charged particle beam inspection system.

[0017] Figure 3B As Figure 3A Schematic diagram of an exemplary multi-pole structure array having a 3x3 configuration of a portion of an exemplary source conversion unit.

[0018] Figure 4 is a graphic representation of the radial and tangential electrostatic field distribution within a multipole structure.

[0019] Figure 5A , Figure 5B , Figure 5C , Figure 5D and Figure 5E is a schematic diagram of an exemplary multipole structure.

[0020] Fig. 6A is a schematic diagram of an exemplary array of multipolar structures consistent with embodiments of the present disclosure.

[0021] Figure 6B Schematically illustrates an embodiment consistent with the present disclosure Fig. 6A An exemplary grouping of multipolar structures of an array of multipolar structures.

[0022] Figure 6C Schematically illustrates an embodiment consistent with the present disclosure Figure 6B Subgrouping of the group shown in .

[0023] Fig. 7A is a schematic diagram of an exemplary array of multipolar structures having multiple layers consistent with embodiments of the present disclosure.

[0024] Figure 7B is consistent with the embodiments of the present disclosure Fig. 7A Schematic diagram of exemplary layers of an array of multipolar structures.

[0025] Fig. 8A and Figure 8B is a schematic diagram of an exemplary array of multipolar structures having multiple layers consistent with embodiments of the present disclosure.

[0026] Figure 8C , Fig.8D and Fig. 8E is consistent with the embodiments of the present disclosure Fig. 8A Schematic diagram of exemplary layers of an array of multipolar structures.

[0027] Fig. 9 is a flow chart illustrating an exemplary method of fabricating an exemplary configuration of an array of multipolar structures consistent with embodiments of the present disclosure. DETAILED DESCRIPTION

[0028] Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings, wherein the same reference numerals in different figures represent the same or similar elements unless otherwise indicated. The implementations set forth in the following description of the exemplary embodiments do not represent all implementations consistent with the present invention. Instead, they are merely examples of devices and methods consistent with various aspects of the present invention described in the appended claims.

[0029] The enhanced computing power of electronic devices can be achieved by significantly increasing the packaging density of circuit components such as transistors, capacitors, diodes, etc. on integrated circuit chips while reducing the physical size of the device. For example, the IC chip of a smart phone (which is the size of a fingernail) can include more than 2 billion transistors, each of which is less than 1 / 1000 the size of a human hair. Therefore, it is obvious that semiconductor IC manufacturing is a complex and time-consuming process that requires hundreds of individual steps. Even if one step goes wrong, it is likely to greatly affect the function of the final product. Even a "killer defect" may cause equipment failure. The goal of the manufacturing process is to improve the overall yield of the process. For example, to achieve a 75% yield for a 50-step process, the yield of each individual step must be greater than 99.4%, and if the yield of the individual step is 95%, the yield of the entire process will drop to 7%.

[0030] While high process yields are desirable in IC chip manufacturing facilities, it is also necessary to maintain high wafer throughput, which is defined as the number of wafers processed per hour. High process yields and high wafer throughput may be affected by the presence of defects, especially when operator intervention is required to view the defects. Therefore, high-throughput detection and identification of micro- and nano-scale defects by inspection tools (such as SEM) is critical to maintaining high yields and low costs.

[0031] The SEM uses a focused primary electron beam to scan the surface of a sample. The primary electrons interact with the sample and generate secondary electrons. The SEM creates an image of the sample scanned area by scanning the sample with the focused beam and capturing the secondary electrons with a detector. For high-throughput inspection, some inspection systems use multiple focused primary electron beams. Since multiple focused beams can scan different parts of the wafer at the same time, a multi-beam inspection system can inspect the wafer at a higher speed than a single-beam inspection system.

[0032] However, in conventional multi-beam inspection systems, increasing the number of focused beams means using more off-axis (not on the main optical axis of the system) focused beams. Off-axis focused beams have phase differences that increase as they are radially offset from the main optical axis, and therefore reduce the quality of the image produced for inspection. In some cases, the increase in aberrations is the result of the need to significantly change the direction of some electron beams to scan the surface of the wafer. When the number of electron beams increases, some electron beams need to be away from the central axis of the scanning device. In order to ensure that all electron beams arrive at the wafer surface at right angles, these eccentric electron beams are more manipulated than other electron beams around the central axis. This higher level of manipulation may cause the image of the sample wafer to be blurred and out of focus. One aspect of the present disclosure relates to systems and methods for minimizing the degradation of image quality by reducing the aberrations of off-axis focused beams. This can be achieved by using an inherently small aberration source conversion unit.

[0033] For clarity, the relative sizes of components in the drawings may be exaggerated. In the following description of the drawings, the same or similar reference numerals refer to the same or similar components or entities, and only the differences with respect to the various embodiments are described. As used herein, unless otherwise specifically stated, the term "or" covers all possible combinations unless not feasible. For example, if it is stated that the database may include A or B, then unless otherwise specified or not feasible, the database may include A, or B, or A and B. As a second example, if it is stated that the database may include A, B, or C, then unless otherwise specified or not feasible, the database may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C.

[0034] Reference now Figure 1 , Figure 1 is a schematic diagram illustrating an exemplary charged particle beam inspection system 100 consistent with embodiments of the present disclosure. Figure 1 As shown, the charged particle beam inspection system 100 includes a main chamber 10, a load lock chamber 20, an electron beam tool 40, and an equipment front end module (EFEM) 30. The electron beam tool 40 is located in the main chamber 10. Although the description and drawings are directed to electron beams, it should be understood that the embodiments are not intended to limit the present disclosure to specific charged particles.

[0035] The EFEM 30 includes a first loading port 30a and a second loading port 30b. The EFEM 30 may include additional (one or more) loading ports. The first loading port 30a and the second loading port 30b may, for example, receive a front opening wafer pod (FOUP) containing wafers (e.g., semiconductor wafers or wafers made of other (one or more) materials) or samples to be inspected (hereinafter, wafers and samples may be collectively referred to as "wafers"). One or more robotic arms (not shown) in the EFEM 30 transport the wafers to the load lock chamber 20.

[0036] The load lock chamber 20 may be connected to a load lock vacuum pump system (not shown) that removes gas molecules in the load lock chamber 20 to reach a first pressure below atmospheric pressure. After reaching the first pressure, one or more robotic arms (not shown) transport the wafer from the load lock chamber 20 to the main chamber 10. The main chamber 10 is connected to a main chamber vacuum pump system (not shown) that removes gas molecules in the main chamber 10 to reach a second pressure below the first pressure. After reaching the second pressure, the wafer is subjected to inspection by an electron beam tool 40. In some embodiments, the electron beam tool 40 may include a single beam inspection tool. In other embodiments, the electron beam tool 40 may include a multi-beam inspection tool.

[0037] The controller 50 is electrically connected to the electron beam tool 40. The controller 50 may be a computer configured to perform various controls of the charged particle beam inspection system 100. The controller 50 may also include processing circuitry configured to perform various signal and image processing functions. Figure 1 30, but it should be understood that the controller 50 can be part of the structure. Although the present disclosure provides an example of a main chamber 10 that houses an electron beam inspection tool, it should be noted that the aspects of the present disclosure in its broadest sense are not limited to chambers that house electron beam inspection tools. Instead, it should be understood that the aforementioned principles can also be applied to other tools that operate at a second pressure.

[0038] Reference now Figure 2 , Figure 2 is a schematic diagram illustrating an exemplary electron beam tool 40 including a multi-beam inspection tool consistent with an embodiment of the present disclosure. The exemplary electron beam tool 40 is Figure 1A portion of an exemplary charged particle beam inspection system 100 of the present invention. A multi-beam electron beam tool 40 (also referred to herein as device 40) includes an electron source 201, a gun body aperture plate 271, a buncher lens 210, a source conversion unit 220, a primary projection system 230, a motorized stage 209, and a sample holder 207 supported by the motorized stage 209 to hold a sample 208 to be inspected (e.g., a wafer or a photomask). The multi-beam electron beam tool 40 may also include a secondary projection system 250 and an electron detection device 240. The primary projection system 230 may include an objective lens 231. The electron detection device 240 may include a plurality of detection elements 241, 242, and 243. A beam splitter 233 and a deflection scanning unit 232 may be positioned inside the primary projection system 230.

[0039] The electron source 201, the gun body aperture plate 271, the condenser lens 210, the source conversion unit 220, the beam splitter 233, the deflection scanning unit 232 and the primary projection system 230 can be aligned with the main optical axis 204 of the device 40. The secondary projection system 250 and the electron detection device 240 can be aligned with the secondary optical axis 251 of the device 40.

[0040] The electron source 201 may include a cathode (not shown) and an extractor or an anode (not shown), wherein during operation, the electron source 201 is configured to emit primary electrons from the cathode and the primary electrons are extracted or accelerated by the extractor and / or the anode to form a primary electron beam 202, which forms a primary beam cross (virtual or real) 203. The primary electron beam 202 can be visualized as being emitted from the primary beam cross 203.

[0041] The source conversion unit 220 may include an imaging element array (eg, Figure 3A An imaging element array 322), an aberration compensator array (e.g., Figure 3A aberration compensator array 324), a beam limiting aperture array (e.g., Figure 3A of beam limiting aperture array 321) and pre-bent micro-deflector array (e.g., Figure 3AThe pre-bent micro-deflector array 323). In some embodiments, the pre-bent micro-deflector array deflects multiple primary sub-beams 211, 212, 213 in the primary electron beam 202 to enter the beam limiting aperture array, the imaging element array and the aberration compensator array from the normal direction. In some embodiments, the beam condenser lens 210 is designed to focus the primary electron beam 202 into a parallel beam and incident on the source conversion unit 220 from the normal direction. The imaging element array may include multiple micro-deflectors or micro-lenses to affect the multiple primary sub-beams 211, 212, 213 of the primary electron beam 202 and form multiple parallel images (virtual or real) of the primary beam cross 203, one parallel image for each primary sub-beam in the primary beams 211, 212 and 213. In some embodiments, the aberration compensator array may include a field curvature compensator array (not shown) and an astigmatism compensator array (not shown). The field curvature compensator array may include a plurality of micro lenses to compensate for the field curvature aberration of the primary beamlets 211, 212, and 213. The astigmatism compensator array may include a plurality of micro astigmatists to compensate for the astigmatism aberration of the primary beamlet 211. The beam limiting aperture array may be configured to limit the diameters of the individual primary beamlets 211, 212, and 213. Figure 2 Three primary sub-beams 211, 212 and 213 are shown as an example, and it can be understood that the source conversion unit 220 can be configured to form any number of primary sub-beams. The controller 50 can be connected to Figure 1 The controller 50 may be used to control various parts of the charged particle beam inspection system 100, such as the source conversion unit 220, the electronic detection device 240, the primary projection system 230, or the motorized stage 209. In some embodiments, as described in further detail below, the controller 50 may perform various image and signal processing functions. The controller 50 may also generate various control signals to manage the operation of the charged particle beam inspection system.

[0042] The buncher lens 210 is configured to focus the primary electron beam 202. The buncher lens 210 may also be configured to adjust the current of the primary sub-beams 211, 212, and 213 downstream of the source conversion unit 220 by changing the focusing power of the buncher lens 210. Alternatively, the current may be changed by changing the radial size of the beam limiting apertures corresponding to the respective primary sub-beams within the beam limiting aperture array. The current may be changed by changing the radial size of the beam limiting apertures and the focusing power of the buncher lens 210. The buncher lens 210 may be a movable buncher lens, and the buncher lens 210 may be configured so that the position of its first principal plane is movable. The movable buncher lens may be configured to be magnetic, which may cause the off-axis sub-beams 212 and 213 to illuminate the source conversion unit 220 at a rotation angle. The rotation angle varies with the focusing power of the movable buncher lens or the position of the first principal plane. The condenser lens 210 may be an anti-rotation condenser lens, which may be configured to maintain a rotation angle when the focusing power of the condenser lens 210 changes. In some embodiments, the condenser lens 210 may be a movable anti-rotation condenser lens, wherein its rotation angle does not change when its focusing power and the position of its first principal plane change.

[0043] The objective lens 231 can be configured to focus the sub-beams 211, 212, and 213 onto the sample 208 for inspection, and in the current embodiment, three detection points 221, 222, and 223 can be formed on the surface of the sample 208. In operation, the gun body aperture plate 271 is configured to block peripheral electrons of the primary electron beam 202 to reduce the Coulomb effect. The Coulomb effect may expand the size of each detection point 221, 222, and 223 of the primary sub-beams 211, 212, and 213, and thus deteriorate the inspection resolution.

[0044] The beam splitter 233 may be, for example, a Wien filter ( Figure 2 The electrostatic deflector generates an electrostatic dipole field and a magnetic dipole field. In operation, the beam splitter 233 can be configured to apply an electrostatic force to each electron of the primary sub-beams 211, 212, and 213 through the electrostatic dipole field. The electrostatic force is equal in magnitude but opposite in direction to the magnetic force applied to each electron by the magnetic dipole field of the beam splitter 233. The primary sub-beams 211, 212, and 213 can therefore pass through the beam splitter 233 at least substantially straight with a deflection angle of at least substantially zero.

[0045] In operation, the deflection scanning unit 232 is configured to deflect the primary beamlets 211, 212, and 213 to scan the detection points 221, 222, and 223 across respective scanning areas in a portion of the surface of the sample 208. In response to the primary beamlets 211, 212, and 213 or the detection points 221, 222, and 223 being incident on the sample 208, electrons emerge from the sample 208 and generate three secondary electron beams 261, 262, and 263. Each of the secondary electron beams 261, 262, and 263 typically includes secondary electrons (having an electron energy of ≤50 eV) and backscattered electrons (having an electron energy between 50 eV and the landing energy of the primary beamlets 211, 212, and 213). The beam splitter 233 is configured to deflect the secondary electron beams 261, 262, and 263 toward the secondary projection system 250. The secondary projection system 250 then focuses the secondary electron beams 261, 262 and 263 onto the detection elements 241, 242 and 243 of the electron detection device 240. The detection elements 241, 242 and 243 are arranged to detect the corresponding secondary electron beams 261, 262 and 263 and generate corresponding signals, which are sent to the controller 50 or a signal processing system (not shown), for example to construct an image of the corresponding scanned area of ​​the sample 208.

[0046] In some embodiments, the detection elements 241, 242, and 243 detect the corresponding secondary electron beams 261, 262, and 263, respectively, and generate corresponding intensity signal outputs (not shown) to an image processing system (e.g., controller 50). In some embodiments, each detection element 241, 242, and 243 may include one or more pixels. The intensity signal output of a detection element may be the sum of the signals generated by all pixels within the detection element.

[0047] In some embodiments, the controller 50 may include an image processing system, which includes an image acquisition device (not shown) and a storage device (not shown). The image acquisition device may include one or more processors. For example, the image acquisition device may include a computer, a server, a mainframe, a terminal, a personal computer, any kind of mobile computing device, or a combination thereof. The image acquisition device may be communicatively coupled to the electronic detection device 240 of the device 40 by means of a medium, such as an electrical conductor, a fiber optic cable, a portable storage medium, IR, Bluetooth, the Internet, a wireless network, radio, or a combination thereof. In some embodiments, the image acquisition device may receive a signal from the electronic detection device 240 and may construct an image. The image acquisition device may thus acquire an image of the sample 208. The image acquisition device may also perform various post-processing functions, such as generating contours, superimposing indications on the acquired image, and the like. The image acquisition device may be configured to perform adjustments to brightness and contrast, etc., on the acquired image. In some embodiments, the storage device may be a storage medium such as a hard disk, a flash drive device, a cloud storage device, a random access memory (RAM), other types of computer-readable memory, and the like. The storage device may be coupled to the image acquirer and may be used to save the scanned raw image data as a raw image and to save a post-processed image.

[0048] In some embodiments, the image acquirer can acquire one or more images of the sample based on the imaging signal received from the electronic detection device 240. The imaging signal can correspond to a scanning operation for performing charged particle imaging. The acquired image can be a single image including multiple imaging areas. The single image can be stored in a storage device. The single image can be an original image that can be divided into multiple regions. Each region can include an imaging area containing features of the sample 208. The acquired image can include multiple images of a single imaging area of ​​the sample 208 sampled multiple times in a time series. Multiple images can be stored in a storage device. In some embodiments, the controller 50 can be configured to perform image processing steps on multiple images of the same position of the sample 208.

[0049] In some embodiments, the controller 50 may include a measurement circuit device (e.g., an analog-to-digital converter) to obtain the distribution of the detected secondary electrons. The electron distribution data collected during the detection time window is combined with the corresponding scan path data of each of the primary sub-beams 211, 212, and 213 incident on the wafer surface, and can be used to reconstruct an image of the inspected wafer structure. The reconstructed image can be used to reveal various features of the internal or external structure of the sample 208, and thus can be used to reveal any defects that may exist in the wafer.

[0050] In some embodiments, the controller 50 may control the motorized stage 209 to move the sample 208 during the inspection of the sample 208. In some embodiments, the controller 50 may enable the motorized stage 209 to continuously move the sample 208 in one direction at a constant speed. In other embodiments, the controller 50 may enable the motorized stage 209 to change the movement speed of the sample 208 over time according to the steps of the scanning process.

[0051] although Figure 2 The apparatus 40 is shown using three primary electron beams, but it should be understood that the apparatus 40 may use two or more primary electron beams. The present disclosure does not limit the number of primary electron beams used in the apparatus 40.

[0052] Reference now Figure 3A , Figure 3A is a schematic diagram of an exemplary multi-beam device consistent with an embodiment of the present disclosure, illustrating Figure 1 An exemplary configuration of a source conversion unit of an exemplary charged particle beam inspection system. In some embodiments, the apparatus 300 may include an electron source 301, a pre-beamlet forming aperture array 372, a buncher lens 310 (similar to Figure 2 The condenser lens 210), the source conversion unit 320 (similar to Figure 2 source conversion unit 220), objective lens 331 (similar to Figure 2 objective lens 231) and sample 308 (similar to Figure 2 The sample 208). The electron source 301, the pre-beamlet forming aperture array 372, the buncher lens 310, the source conversion unit 320 and the objective lens 331 are aligned with the main optical axis 304 of the device. The electron source 301 generates a primary electron beam 302 along the main optical axis 304 and having a source crossover (virtual or real) 301S. The pre-beamlet forming aperture array 372 cuts the peripheral electrons of the primary electron beam 302 to reduce the Coulomb effect. The primary electron beam 302 can be trimmed into three beamlets 311, 312 and 313 by the pre-beamlet forming aperture array 372 of the pre-beamlet forming mechanism.

[0053] In some embodiments, the source conversion unit 320 may include a beamlet limiting aperture array 321 having a beam limiting aperture, the beamlet limiting aperture array 321 being configured to limit beamlets 311, 312, and 313 of the primary electron beam 302. The source conversion unit 320 may also include an imaging element array 322 having imaging micro deflectors 322_1, 322_2, and 322_3, the imaging micro deflectors being configured to deflect the beamlets 311, 312, and 313 toward the optical axis 304 to form a virtual image of the source intersection 301S. The virtual image is projected onto the sample 308 through the objective lens 331 and forms detection points 391, 392, and 393 thereon. The source conversion unit 320 may also include an aberration compensator array 324, the aberration compensator array 324 being configured to compensate for the aberrations of the detection points 391, 392, and 393. In some embodiments, the aberration compensator array 324 may include a field curvature compensator array (not shown) having micro lenses, which are respectively configured to compensate for the field curvature aberrations of the detection points 391, 392, and 393. In some embodiments, the aberration compensator array 324 may include an astigmatism compensator array (not shown) having micro astigmatists, which are respectively configured to compensate for the astigmatism aberrations of the detection points 391, 392, and 393.

[0054] In some embodiments, the source conversion unit 320 may further include a pre-bent micro-deflector array 323, wherein the pre-bent micro-deflector array 323 has pre-bent micro-deflectors 323_1, 323_2, and 323_3 for respectively bending the sub-beams 311, 312, and 313 to be incident on the sub-beam limiting aperture array 321 in a normal direction. In some embodiments, the beam condenser lens 310 may focus the three sub-beams 311, 313, and 313 into parallel beams along the main optical axis 304 and vertically incident on the source conversion unit 320.

[0055] In some embodiments, the imaging element array 322, the aberration compensator array 324, and the pre-curved micro-deflector array 323 may include multiple layers of micro-deflectors, micro-lenses, or micro-astigmatists.

[0056] In the source conversion unit 320, the sub-beams 311, 312 and 313 of the primary electron beam 302 are respectively deflected toward the main optical axis 304 by the micro-deflectors 322_1, 322_2 and 322_3 of the imaging element array 322. It should be understood that the sub-beam 311 may be on the optical axis 304 before reaching the micro-deflector 322_1; therefore, the sub-beam 311 may not be deflected by the micro-deflector 322_1.

[0057] The objective lens 331 focuses the beamlets onto the surface of the sample 308, i.e., projects three virtual images onto the sample surface. The three images formed on the sample surface by the three beamlets 311-313 form three detection points 391, 392, and 393 thereon. The deflection angles of the beamlets 311-313 are adjusted to reduce the off-axis aberrations of the three detection points 391-393 due to the objective lens 331, so that the three deflected beamlets pass through or approach the front focus of the objective lens 331.

[0058] The deflection angle of a beamlet deflected by a microdeflector (e.g., a microdeflector in the imaging element array 322) corresponds to the radial offset of the beamlet (i.e., the distance from the optical axis 304 to the corresponding beamlet). The deflection angle increases with increasing radial offset. Beamlets with the same radial offset have the same or substantially the same deflection angle. For example, as in Figure 3B As shown in the exemplary multipole structure array with a 3x3 array configuration in FIG, if the radial offsets 328 and 329 of the micro deflector 322_2 and the micro deflector 322_3 are the same, the deflection angle of the micro deflector 322_2 can be equal to the deflection angle of the micro deflector 322_3. In addition, the deflection direction of the sub-beam is related to its corresponding radial offset direction. In addition, the aberrations (e.g., field curvature aberration and astigmatism aberration) of the sub-beam increase with the increase of the radial offset. The aberrations of the sub-beams with the same or substantially the same radial offset are the same or substantially the same, and the direction of the astigmatism aberration is related to the direction of their radial offset.

[0059] Figure 3B A 3x3 imaging microdeflector array configuration is shown that can simultaneously deflect a total of nine beamlets. As the number of beamlets increases, the size of the array also increases. Therefore, in a large imaging microdeflector array, some beamlets will be located farther away from the optical axis of the device (e.g., Figure 3A The deflection aberration generated by the micro-deflector increases with the increase of its deflection angle. Therefore, the non-uniformity of the corresponding detection point increases with the increase of the number of beamlets. Figure 3B An imaging micro-deflector array is taken as an example, but it can be understood that a similar relationship between deflection aberration and array size may also exist in other types of micro-deflector arrays.

[0060] Reference now Figure 4 , Figure 4 The radial and tangential components E of the electric field E at a spatial point (r, θ) inside the deflector with a central axis are shown in Figure 1. r and E θ can be expressed as equations (1) and (2) respectively:

[0061]

[0062] The Kth-order electric field E k The intensity and direction angle α k For E k = k·r k-1 ·d k and α k = kθ.d k is the K-order component on the central axis or is called the K-order on-axis component. Therefore, Figure 4 The E1 shown is E1 = d1 and α k =θ. The strength and direction of the first-order electric field E1 do not vary with r or θ. Therefore, the first-order electric field (i.e., the E1 field or d1 component) is required to deflect the electron beam, while other higher-order on-axis components (e.g., d 2n+1 ) needs to be reduced or even eliminated. The larger the deflection angle, the stronger the E1 field or d1 component is required.

[0063] A multi-equal-pole deflector can be defined as a multi-pole structure deflector having a central axis and an even number of pole electrodes (e.g., 2, 4, 6, 8, 10, etc.). In a cross section perpendicular to the central axis of the deflector, the inner contours of all pole electrodes are within a circle with a radius R and are equally divided by an arc angle β. For example, Figure 5A , Figure 5B , Figure 5C , Figure 5D and Figure 5E Deflectors with four, six, eight, ten and twelve pole electrodes and arc angles β of 90°, 60°, 45°, 36° and 30° are shown, respectively.

[0064] The number P of pole electrodes em in the multi-equal polarity deflector, the split angle β and the potential can be configured to generate d1 while making d2n+1 as small as possible. The pole electrodes em are counted counterclockwise from the X axis. For example, Figure 5A , electrodes 511, 512, 513 and 514 are e1, e2, e3 and e4 respectively. Table 1 shows the mTo generate an excitation setting of a relative excitation voltage of E1 parallel to the X-axis. According to Table 1, Table 2 shows the on-axis component of the electric field relative to the number of pole electrodes. By rotating the relative excitation voltage setting in Table 1 by one or more pole electrodes, as shown in Table 3, E1 will be rotated one or more times of the arc angle β accordingly. In Table 3, the excitation setting in Table 1 is rotated by 1 times the arc angle of the 4-pole deflector and the 6-pole deflector, 2 times the arc angle of the 8-pole deflector and the 10-pole deflector, and 3 times the arc angle of the 12-pole deflector. By combining the excitation settings in Table 1 and Table 3 and adjusting the base voltage V1 of Table 1 and the base voltage V2 of Table 3, as shown in Table 4, E1 of arbitrary direction and arbitrary intensity can be generated, and the on-axis component of the electric field relative to the number of pole electrodes is the same as that in Table 2. In addition, as shown in Table 2, some high-order components of the electric field can be eliminated by using a deflector with a greater number of pole electrodes.

[0065] Table 1

[0066]

[0067] Table 2

[0068]

[0069]

[0070] Table 3

[0071]

[0072] Table 4

[0073]

[0074]

[0075] For example, as shown in Table 2, the 4-equal-pole deflector has all high-order components d 2n+1 In contrast, the 6-equal-pole deflector does not have some high-order components (e.g., d3, d9, and d 15 When using a 12-equal-pole deflector, many high-order components disappear (e.g., d3, d5, d7, d9, d 15 and d 17 ). Generally, the high-order components become zero within a period related to the number of deflector poles. For example, the order k of the zero component is related to the number of poles (P=4+2p) as shown in the following equation (3):

[0076] K = 1 + 2i + n(4 + 2p) (3);

[0077] Where p, n and i are integers, i = 1, 2, ... p, n = 0, 1, 2, ... ∞. In some embodiments, farther away from the optical axis of the device (e.g., Figure 3A A micro-deflector closer to the optical axis 304) can be configured to have a greater number of pole electrodes than a micro-deflector closer to the optical axis to reduce more high-order on-axis components.

[0078] For non-zero components d k , the corresponding electric field E k (r, θ) varies with the ratio of the radial position r of the deflector to the inner radius R to the k-1 power and the first component dl. Therefore, Ek can be reduced by reducing the ratio. In some embodiments, away from the optical axis of the device (e.g., Figure 3A Micro-deflectors close to the optical axis 304) can be configured to have a larger inner radius than micro-deflectors close to the optical axis to reduce the non-zero electric field Ek.

[0079] Reference now Fig. 6A , Figure 6B and Figure 6C , which are schematic diagrams of exemplary multi-pole structure arrays 622 consistent with embodiments of the present disclosure. The multi-pole structure array 622 may be a source conversion unit (such as Figure 3A Specifically, the multi-pole structure array 622 may be an imaging element array (such as Figure 3A imaging element array 322) or a pre-bent micro-deflector array (such as Figure 3A In some embodiments, the multipolar structure array 622 may include a plurality of microdeflectors 622_1-622_49. Using this 7x7 array configuration, 49 charged particle beams (e.g., electron beams) may be simultaneously deflected to form a detection point on the sample surface. In some embodiments, the central axis of the microdeflector (e.g., microdeflector 622_1) located in the middle of the array may be aligned with the optical axis 604 (e.g., Figure 3A The optical axis 304) is aligned. Fig. 6A , Figure 6B and Figure 6C One embodiment of an array of multi-pole structures having a 7x7 configuration is shown, but it will be appreciated that the array may be any size.

[0080] Some of the forty-nine micro-deflectors 622_1-622_49 are located on the outer portion of the array structure and farther from the optical axis 604 than others, thereby having a larger radial offset. For example, the micro-deflectors at the four corners (i.e., micro-deflectors 622_29, 622_35, 622_41, and 622_47) are located farthest from the optical axis 604 and may have to generate the largest deflection angles. In addition, when moving rightward along the X-axis from micro-deflector 622_1 to micro-deflector 622_26, the corresponding radial offset (distance from the optical axis 604) increases.

[0081] In order to reduce the high-order components of the electric field generated by these external micro-deflectors, and thereby reduce the deflection aberrations and inhomogeneities produced at the corresponding detection points, micro-deflectors with more polar electrodes can be used to deflect the corresponding beams. In addition, the inner radius R of the micro-deflector with a larger radial offset can be larger than the inner radius of the micro-deflector with a smaller radial offset. Therefore, Fig. 6A As shown in FIG. 6 , moving along the X-axis, the micro deflector 622_1 may include six poles, the micro deflector 622_2 may include eight poles, the micro deflector 622_10 may include ten poles, and the micro deflector 622_26 may include twelve poles. In some embodiments, the inner radius R of the micro deflector 622_2 may be greater than the inner radius of the micro deflector 622_1, the inner radius R of the micro deflector 622_10 may be greater than the inner radius of the micro deflector 622_2, and the inner radius R of the micro deflector 622_26 may be greater than the inner radius of the micro deflector 622_10.

[0082] Figure 6B An exemplary grouping of micro-deflectors based on the proximity of radial offset to the optical axis is illustrated. For example, micro-deflectors with radial offset differences within a range of <50% can be classified into one group. In some embodiments, all micro-deflectors in a group can use the same type of micro-deflector. For example, Group 1 (in Figure 6B Group 2 (in the example of FIG. 1 ) includes a micro deflector (e.g., micro deflector 622_1) in the middle of the array, and the micro deflector in the middle of the array may include a 6-pole micro deflector. Figure 6B Group 3 (in the example of FIG. 1 ) includes eight micro-deflectors (e.g., micro-deflectors 622_2-622_9) surrounding Group 1, which may include 8-pole micro-deflectors. Figure 6B Group 4 (in FIG. 1 ) includes 16 micro deflectors (e.g., micro deflectors 622_10-622_25) surrounding Group 2, which may use 10 micro deflectors. Figure 6B, labeled as G4) includes twenty-four micro-deflectors (e.g., micro-deflectors 622_26-622_49) surrounding group 4, which may include 12-pole micro-deflectors.

[0083] Despite Figure 6B In the embodiment, different groups include microdeflectors with different pole numbers, but it is understood that some different groups may include microdeflectors with the same number of poles. For example, in some embodiments, if the difference in deflection aberration between group 1 and group 2 is within an acceptable range, the microdeflectors in group 1 and group 2 (e.g., microdeflectors 622_1-622_9) may all use 6-pole microdeflectors. In such embodiments, groups 3 and 4 may use microdeflectors with more pole numbers, such as 8-pole, 10-pole, 12-pole, or more.

[0084] As mentioned earlier Fig. 6A As described, for those micro-deflectors having the same radial offset with the optical axis 604 of the device, such as the micro-deflectors at the four corners (i.e., micro-deflectors 622_29, 622-35, 622_41, and 622_47), the deflection angles of the corresponding beams can be equal or substantially equal. In addition, those micro-deflectors having the same deflection angle can be configured to have the same orientation angle. Therefore, in the multi-pole structure array 622, groups of multi-pole deflectors having the same or substantially the same radial offset and the same or substantially the same orientation angle can be grouped to share a common driver (the common driver performs various control functions, such as generating an excitation voltage for each electrode, controlling the deflection characteristics, and driving the control signal to the micro-deflector). By sharing a common driver for multiple micro-deflectors configured to deflect corresponding beams at the same deflection angle, the number of connection circuits in the array configuration can be reduced because a common voltage set can be wired to all micro-deflectors in the group. Examples of drive sharing techniques may be found in US Application No. 62 / 665,451, which is incorporated by reference in its entirety.

[0085] Figure 6CAn exemplary subgrouping of a micro-deflector group based on a desired deflection angle is illustrated. Among the micro-deflectors of group 4, micro-deflectors having the same or substantially the same radial offset can be subgrouped together and share a common driver. For example, four micro-deflectors (micro-deflectors at the corners) labeled G4_SG1 can be grouped together as subgroup 1. Similarly, eight micro-deflectors (neighbors of subgroup 1) labeled G4_SG2 can be grouped together as subgroup 2; eight micro-deflectors (neighbors of subgroup 2) labeled G4_SG3 can be grouped together as subgroup 3; and four micro-deflectors (micro-deflectors on the X-axis or Y-axis) labeled G4_SG4 ​​can be grouped together as subgroup 4. Because the micro-deflectors in each subgroup have the same or substantially the same radial offset (and therefore have the same deflection angle) and have the same number of poles, those micro-deflectors in the subgroup can be connected to a common driver.

[0086] Reference now Fig. 7A , Fig. 7A is a schematic diagram of an exemplary multi-pole structure array 722 having multiple layers consistent with an embodiment of the present disclosure. The multi-pole structure array 722 may be a source conversion unit (such as Figure 3A Specifically, the multi-pole structure array 722 can be used as an imaging element array (such as Figure 3A imaging element array 322) or a pre-bent micro-deflector array (such as Figure 3A pre-bent micro-deflector array 323).

[0087] In some embodiments, the multipole structure array 722 may include multiple multipole structure layers, such as layers 722a and 722b, and each layer may include multiple multipole structures (e.g., micro-deflectors). For example, layer 722a may include micro-deflectors 722a_1-722a_5. Similarly, layer 722b may include micro-deflectors 722b_1-722b_5. In some embodiments, the center of the layer may be aligned with the optical axis 704 of the device. The center of the micro-deflector in the middle of each layer (e.g., 722a_1 and 722b_1) may be aligned with the optical axis 704.

[0088] In some embodiments, the micro-deflector pairs from each layer can be aligned together and deflect the corresponding beams. For example, 722a_1 and 722b_1 can both deflect beam 711. Similarly, 722a_2 and 722b_2 can both deflect beam 712; 722a_3 and 722b_3 can both deflect beam 713; 722a_4 and 722b_4 can both deflect beam 714; and 722a_5 and 722b_5 can both deflect beam 715. In a multi-layer configuration, because the micro-deflector pairs are connected in series to deflect a single beam, the desired deflection angle of each micro-deflector can be less than the deflection angle in a single-layer configuration.

[0089] In some embodiments, the micro-deflector pair may use the same type of micro-deflectors with the same number of poles. For example, micro-deflectors 722a_1 and 722b_1 may each include an 8-pole micro-deflector. In other embodiments, the micro-deflector pair may use different types of micro-deflectors. For example, micro-deflector 722a_4 may use a 12-pole micro-deflector, while micro-deflector 722b_4 may use a 10-pole micro-deflector.

[0090] Reference now Figure 7B , Figure 7B is consistent with the embodiments of the present disclosure Fig. 6A , Figure 6B and Figure 6C Schematic diagram of an exemplary layer of a multipole structure array. As the number of beams increases, the size of the multipole structure array also increases. Therefore, in a large array of micro-deflectors, some beams will be located farther away from the optical axis of the device (e.g., Figure 3A The deflection angle of the micro-deflectors at the outer edge of the array is also increased accordingly. Due to the larger deflection angle, the beams deflected by these micro-deflectors at the outer edge may be subject to higher deflection aberrations, thereby increasing the size and non-uniformity of the corresponding detection points. Fig. 6A As described, in order to reduce the high-order components of the electric field generated by these microdeflectors (thereby reducing the deflection aberrations and inhomogeneities at the corresponding detection points), microdeflectors with more polar electrodes can be used to deflect the corresponding beams. The same approach can also be used for multi-layer microdeflector arrays.

[0091] Figure 7B An example of a 3x3 micro-deflector array consistent with an embodiment of the present disclosure is shown. The array may be a layer of a multi-layer micro-deflector array, such as Fig. 7A 722a or 722b of the array 722. As described in connection with 6A and Figure 6BAs described, the nine micro-deflectors 750_1-750_9 can be grouped based on radial offset. For example, the first group can include micro-deflector 750_1, which has the lowest radial offset among the nine micro-deflectors. The second group can include micro-deflectors on the X-axis and Y-axis (e.g., micro-deflectors 750_2, 750_4, 750_6, 750_8), and the second group has a higher radial offset than the first group (e.g., micro-deflector 750_1). The third group can include micro-deflectors at the four corners (e.g., micro-deflectors 750_3, 750_5, 750_7, 750_9), and the third group has the largest radial offset from the optical axis 704. Therefore, the first group (micro deflector 751_1), the second group (micro deflectors 750_2, 750_4, 750_6, 750_8) and the third group (micro deflectors 750_3, 750_5, 750_7, 750_9) can respectively include 6-pole micro deflectors, 8-pole micro deflectors and 12-pole micro deflectors to reduce the high-order components of the electric field, thereby reducing the deflection aberration and non-uniformity of the corresponding detection point. Figure 7B A 3x3 array configuration is shown, but it should be understood that the array can be any size. Figure 7B Three groups are shown, each group having a different type of micro-deflector, but it will be understood that the array may include any combination of groups and types of micro-deflectors.

[0092] In addition, regarding Figure 6C The described driver sharing technology can also be applied to multi-layer micro-deflector arrays. For example, the first group (micro-deflector 750_1) can be connected and driven by the first driver. Similarly, all micro-deflectors in the second group (micro-deflectors 750_2, 750_4, 750_6, 750_8) can be connected and driven by the second driver because these micro-deflectors have the same deflection angle. Similarly, all micro-deflectors in the third group (micro-deflectors 750_3, 750_5, 750_7, 750_9) can be connected and driven by the third driver.

[0093] Reference now Fig. 8A and Figure 8B , Fig. 8A and Figure 8B 8 is a schematic diagram of an exemplary multi-pole structure array having multiple layers consistent with an embodiment of the present disclosure. The multi-pole structure array 822 may be a source conversion unit (such as Figure 3A Specifically, the multi-pole structure array 822 can be used as an imaging element array (such as Figure 3A imaging element array 322) or a pre-bent micro-deflector array (such as Figure 3A pre-bent micro-deflector array 323).

[0094] In some embodiments with multiple micro-deflectors, some particle beams can be deflected by micro-deflectors in one layer, while other particle beams can be deflected by micro-deflectors in another layer. For example, beams 811, 814, and 815 can be deflected by micro-deflectors 822a_1, 822a_4, and 822a_5 in layer 822a, while beams 812 and 813 can be deflected by micro-deflectors 822b_2 and 822b_32b in layer 822b_2. By placing some micro-deflectors in one layer and other micro-deflectors in another layer, the circuits connecting the poles in each layer can be reduced compared to encapsulating the entire micro-deflector set in one layer. Therefore, this can improve electrical safety and also reduce the complexity of the design and manufacturing process of the multi-pole structure array.

[0095] In some embodiments, layers 822a and 822b may include beam path apertures 822a_2, 822a_3, 822b_1, 822b_4, and 822b_5 that allow the beam to pass through without deflection. Figure 8B As shown, because the beam path apertures are narrower than the micro deflectors (e.g., the width of the beam path aperture 822a_3 is narrower than the width of the micro deflector 822a_1), the total width of the array 822 can be reduced by Fig. 8A and Figure 8B As shown, the micro-deflectors are placed alternately to reduce.

[0096] Reference now Figure 8C , Fig.8D and Fig. 8E , Figure 8C , Fig.8D and Fig. 8E The diagram shows an embodiment consistent with the present disclosure. Fig. 8A Schematic diagram of exemplary layers used within a multipole structure array 822. As the number of beams increases, the size of the multipole structure array also increases. Thus, in a large array of micro-deflectors, some beams are located farther away from the optical axis of the device (e.g., Figure 3A The deflection angle of the micro-deflectors located at the outer edge of the structure array 822 is also increased accordingly. Due to the larger deflection angle, the beams deflected by these micro-deflectors located at the outer edge may be subject to higher deflection aberrations, thereby increasing the size and non-uniformity of the corresponding detection points. Fig. 6A As described, in order to reduce the high-order components of the electric field generated by these microdeflectors, and thus reduce the deflection aberrations and inhomogeneities of the corresponding detection points, microdeflectors with a greater number of pole electrodes can be used to deflect the corresponding beams. The same approach can also be used for multi-layer microdeflector arrays, such as Fig. 8A Array 822.

[0097] Figure 8C An exemplary micro-deflector array layer pair that can simultaneously deflect 25 particle beams (5x5 configuration) is shown. In this embodiment, the micro-deflectors (such as Figure 8B micro-deflectors 822a_1, 822a_4, 822a_5) and beam path apertures (such as Figure 8B The beam path holes 822a_2 and 822a_3) are arranged alternately in each layer so that one particle beam is deflected by the micro-deflectors in only one layer. For example, layer 822A includes microdeflectors 822a_1, 822a_3, 822a_5, 822a_7, 822a_9, 822a_10, 822a_12, 822a_14, 822a_16, 822a_18, 822a_20, 822a_22, 822a_24 and beam path holes 822a_2, 822a_4, 822a_6, 822a_8, 822a_11, 822a_13, 822a_15, 822a_17, 822a_19, 822a_21, 822a_23, 822a_25. Similarly, layer 822b includes microdeflectors 822b_2, 822b_4, 822b_6, 822b_8, 822b_11, 822b_13, 822b_15, 822b_17, 822b_19, 822b_21, 822b_23, 822b_25 and beam path holes 822b_1, 822b_3, 822b_5, 822b_7, 822b_9, 822b_10, 822b_12, 822b_14, 822b_16, 822b_18, 822b_20, 822b_22, 822b_24. Therefore, 13 of the 25 beams are deflected by the micro-deflectors of layer 822a, while the remaining 12 beams are deflected by the micro-deflectors of layer 822b.

[0098] Similar to the previous embodiments, micro-deflectors with the same or similar radial offset (e.g., radial offset difference within a range of <50%) can be grouped together and have a certain number of pole electrodes to reduce deflection aberrations. For example, in layer 822a, micro-deflector 822a_1 is a 6-pole micro-deflector, micro-deflectors 822a_3, 822a_5, 822a_7, 822a_9 are 8-pole micro-deflectors, and micro-deflectors 822a_10, 822a_12, 822a_14, 822a_16, 822a_18, 822a_20, 822a_22, and 822a_24 are 10-pole micro-deflectors. Similarly, in the 822b layer, micro deflectors 822b_2, 822b_4, 822b_6, 822b_8 are 8-pole micro deflectors, and micro deflectors 822b_11, 822b_13, 822b_15, 822b_17, 822b_19, 822b_21, 822b_23, and 822b_25 are 10-pole micro deflectors. Figure 8C A 5x5 array configuration is shown, but it should be understood that the array can be any size. Furthermore, it should be understood that the array configuration can include any combination of groups and types of micro-deflectors.

[0099] In addition, regarding Figure 6C and Figure 7B The driver sharing technology described can also be applied to this embodiment. For example, in layer 822b, all micro-deflectors in the first group (micro-deflectors 822b_2, 822b_4, 822b_6, 822b_8) can be connected and driven by the first driver because these micro-deflectors have the same deflection angle and the same number of pole electrodes. Similarly, all micro-deflectors in the second group (micro-deflectors 822b_11, 822b_13, 822b_15, 822b_17, 822b_19, 822b_21, 822b_23 and 822b_25) can be connected and driven by the second driver.

[0100] Fig.8D and Fig. 8E Another embodiment of a microdeflector array layer that can deflect forty-nine particle beams (7x7 configuration) simultaneously is shown. In this embodiment, microdeflectors with a certain number of pole electrodes are placed in one layer. For example, all microdeflectors with six poles or ten poles are placed in one layer. Fig.8D All microdeflectors with eight poles and twelve poles are placed in Fig. 8EIn layer 822b. Of the total forty-nine beams, seventeen beams are deflected by layer 822a, and the remaining thirty-two beams are deflected by layer 822b. In layer 822a, the first group includes a micro-deflector 822a_1 located in the middle, and micro-deflector 822a_1 may include six poles. The second group includes micro-deflectors 822a_10-822a_25 that may include ten poles. Similarly, in layer 822b, the third group includes micro-deflectors 822b_2-822b_9 that may include eight poles. The fourth group includes micro-deflectors 822b_26-822b_49 that may include twelve poles. In addition, with respect to Figure 6C and Figure 7B The drive sharing techniques described in can also be applied to this embodiment. Fig. 8E In the layer 822b of FIG. 1 , four micro deflectors (e.g., micro deflectors 822b_2, 822b_4, 822b_6, 822b_8) in the third group located on one of the X-axis or the Y-axis can be connected and driven by one common driver because those micro deflectors have the same deflection angle, the same orientation angle, and the same number of pole electrodes. Similarly, the other four micro deflectors (e.g., micro deflectors 822b_3, 822b_5, 822b_7, 822b_9) in the third group located at the corners can be connected and driven by another common driver.

[0101] Reference now Fig. 9 , Fig. 9 is a flow chart illustrating an exemplary method of manufacturing an exemplary configuration of a multipolar structure array consistent with embodiments of the present disclosure. In some embodiments, the multipolar structure array can be manufactured using a semiconductor manufacturing process. In some embodiments, the multipolar structure array can include a micro-deflector array, such as Fig. 6A The micro-deflector array 622. In some embodiments, the multi-pole structure array may include a plurality of micro-deflectors, such as Fig. 6A In order to reduce the high-order components of the electric field generated by the micro-deflector, thereby reducing the deflection aberration and non-uniformity of the corresponding detection point, a micro-deflector with a larger number of pole electrodes can be used to deflect the corresponding beam farther from the optical axis of the inspection device. Fig. 6A The micro-deflector 622_29) is larger than the second multi-pole structure (such as Fig. 6A The micro-deflector 622_3) has a higher radial offset (ie, further away from the optical axis), the first multipole structure may include a micro-deflector having a greater number of pole electrodes than the second micro-deflector.

[0102] In step 910, the number of pole electrodes of the first multipole structure is configured based on the deflection aberration characteristics of the first multipole structure. In step 920, the number of pole electrodes of the second multipole structure is configured based on the deflection aberration characteristics of the second multipole structure. The number of pole electrodes selected for the second multipole structure in step 920 is less than the number of pole electrodes selected for the first multipole structure in step 910.

[0103] In step 930, a first multipole structure is formed at a position having a first radial offset from the central axis of the array. In step 940, a second multipole structure is formed at a position having a second radial offset from the central axis of the array. The distance between the optical axis and the position of the first multipole structure is greater than the distance between the optical axis and the position of the second multipole structure. Therefore, the first multipole structure has a larger radial offset than the second multipole structure.

[0104] It will be appreciated that the first multipolar structure and the second multipolar structure may be as described above with respect to, for example, Figure 6B Furthermore, it should be understood that, as mentioned above with respect to e.g. Figure 8C As explained, the first multipole structure and the second multipole structure may be located on separate layers.

[0105] The embodiments may be further described using the following terms:

[0106] 1. A microstructure deflector array, comprising a plurality of multipole structures, each of which comprises a plurality of polar electrodes, the array comprising:

[0107] a first multipole structure of the plurality of multipole structures, the first multipole structure having a first radial offset from a central axis of the array; and

[0108] a second multipole structure of the plurality of multipole structures, the second multipole structure having a second radial offset from a central axis of the array,

[0109] The first radial offset is greater than the second radial offset, and the first multipole structure includes a greater number of pole electrodes than the second multipole structure.

[0110] 2. An array according to clause 1, wherein the first multipole structure comprises a greater number of pole electrodes than the second multipole structure to reduce deflection aberrations when the plurality of multipole structures deflect the plurality of charged particle beams.

[0111] 3. An array according to any one of clauses 1 and 2, wherein:

[0112] The plurality of electrodes of the first multi-pole structure are electrically connected and driven by a first driver, and

[0113] The plurality of electrodes of the second multi-pole structure are electrically connected and driven by a second driver.

[0114] 4. An array according to clause 3, wherein the first driver and the second driver are configured to enable the first multipole structure and the second multipole structure to be used as imaging elements or pre-bent micro-deflectors in a multi-beam device to deflect multiple charged particle beams.

[0115] 5. An array according to any of clauses 1 to 4, wherein the first multipole structure has an inner diameter that is larger than the inner diameter of the second multipole structure.

[0116] 6. A microstructure deflector array, comprising a plurality of multipole structures, each multipole structure comprising a plurality of polar electrodes, the array comprising:

[0117] a first group of multipole structures of the plurality of multipole structures, the first group of multipole structures having a first set of radial offsets from a central axis of the array, wherein each multipole structure in the first group includes a same number of corresponding polar electrodes; and

[0118] a second group of multipole structures of the plurality of multipole structures, the second group of multipole structures having a second set of radial offsets from a central axis of the array, wherein each multipole structure in the second group includes the same number of corresponding polar electrodes,

[0119] Wherein a minimum value of the radial offset in the first set of radial offsets is higher than a maximum value of the radial offset in the second set of radial offsets, and the multipole structures in the first group include a greater number of pole electrodes than the multipole structures in the second group.

[0120] 7. An array according to clause 6, wherein the multipole structures in the first group include a greater number of pole electrodes than the multipole structures in the second group to reduce deflection aberrations when the plurality of multipole structures deflect the plurality of charged particle beams.

[0121] 8. An array according to any of clauses 6 and 7, wherein the first group or the second group may comprise only one multipole structure.

[0122] 9. An array according to any of clauses 6 to 8, wherein a first group of multipole structures in the plurality of multipole structures comprises:

[0123] A first subset of the multi-pole structures is electrically connected and driven by a first driver, wherein radial offsets and orientation angles of the first subset of the multi-pole structures are equal or substantially equal.

[0124] 10. An array according to any of clauses 6 to 9, wherein a second group of multipole structures in the plurality of multipole structures comprises:

[0125] A second subset of the multi-pole structures is electrically connected and driven by a second driver, wherein radial offsets and orientation angles of the second subset of the multi-pole structures are equal or substantially equal.

[0126] 11. An array according to any of clauses 6 to 10, wherein at least one of the first drive and the second drive is configured to enable the corresponding multipole structure to be used as an imaging element or a pre-bent micro-deflector in a multi-beam device to deflect multiple charged particle beams.

[0127] 12. An array according to any of clauses 6-11, wherein the inner diameter of one multipole structure of the first group is larger than the inner diameter of one multipole structure of the second group.

[0128] 13. A microstructure deflector array, comprising a plurality of multipole structures configured to deflect a plurality of charged particle beams, each multipole structure comprising a plurality of pole electrodes, the array comprising:

[0129] a first layer of multipole structures in the plurality of multipole structures, the first layer comprising a first multipole structure having a first radial offset from a central axis of the array and a second multipole structure having a second radial offset from the central axis of the array, wherein the first radial offset is greater than the second radial offset and the first multipole structure comprises a greater number of pole electrodes than the second multipole structure; and

[0130] A second layer of multipole structures in the plurality of multipole structures, the second layer comprising a third multipole structure, the third multipole structure having a third radial offset from a central axis of the array.

[0131] 14. The array according to clause 13, wherein the first multipole structure comprises a greater number of pole electrodes than the second multipole structure to reduce deflection aberrations of the corresponding charged particle beam.

[0132] 15. An array according to any of clauses 13 and 14, wherein the third radial offset is less than the first radial offset.

[0133] 16. The array of clause 15, wherein the third radial offset is greater than the second radial offset.

[0134] 17. An array according to any of clauses 13-16, wherein the number of pole electrodes of the third multipole structure is greater than or equal to the number of pole electrodes of the second multipole structure.

[0135] 18. An array according to any of clauses 13-16, wherein the number of pole electrodes of the third multipole structure is less than or equal to the number of pole electrodes of the first multipole structure.

[0136] 19. An array according to any of clauses 13, 14, 16 and 17, wherein the third multipole structure comprises a greater or equal number of pole electrodes than the first multipole structure.

[0137] 20. The array according to any of clauses 13-19, wherein one of the plurality of charged particle beams is deflected by a multipole structure in a first layer and another of the plurality of charged particle beams is deflected by a multipole structure in a second layer.

[0138] 21. An array according to any of clauses 13-19, wherein one of the plurality of charged particle beams is deflected by a multipole structure in a first layer and a multipole structure in a second layer connected in series, and the multipole structures in the first layer and the multipole structures in the second layer are aligned with each other.

[0139] 22. An array according to any of clauses 13-19, wherein:

[0140] A first beam of the plurality of charged particle beams is deflected by a multipole structure in the first layer,

[0141] A second beam of the plurality of charged particle beams is deflected by a multipole structure in the second layer, and

[0142] A third beam of the plurality of charged particle beams is deflected by the multipole structure in the first layer and the multipole structure in the second layer in series.

[0143] 23. The array according to any of clauses 13-22, wherein each multipole structure of the plurality of multipole structures is placed inside an electrically shielded cavity to be electrically shielded from the other multipole structures.

[0144] 24. An array according to any of clauses 13-23, wherein an inner diameter of a first multipole structure in the first layer is greater than an inner diameter of a second multipole structure in the first layer.

[0145] 25. An array according to any of clauses 13-24, wherein two or more of the multipolar structures in the first layer:

[0146] With the same number of electrodes,

[0147] are equal or substantially equal in radial offset and orientation angle, and

[0148] The first driver is electrically connected to and driven by the first driver.

[0149] 26. An array according to any of clauses 13 to 25, wherein two or more of the multipolar structures in the second layer:

[0150] With the same number of electrodes,

[0151] are equal or substantially equal in radial offset and orientation angle, and

[0152] Electrically connected to and driven by a second driver.

[0153] 27. A source conversion unit in a charged particle beam system, comprising an array according to any of clauses 13-26.

[0154] 28. A method of manufacturing a microstructure deflector array comprising a plurality of multipole structures, each multipole structure comprising a plurality of polar electrodes, the method comprising:

[0155] forming a first multipole structure to have a first radial offset from a central axis of the array; and

[0156] The second multipole structure is formed to have a second radial offset from a central axis of the array, wherein the first radial offset is greater than the second radial offset and the first multipole structure has a different number of pole electrodes than the second multipole structure.

[0157] 29. The method of clause 28, further comprising selecting a number of pole electrodes for the first multipole structure and a number of pole electrodes for the second multipole structure based on aberration characteristics of the first multipole structure and the second multipole structure.

[0158] 30. The method of clause 29, wherein selecting the number of pole electrodes of the first multipole structure and the number of pole electrodes of the second multipole structure comprises selecting the corresponding number of pole electrodes to reduce high-order components of their electric fields.

[0159] 31. The method according to any of clauses 28-30, wherein the number of pole electrodes of the first multipolar structure is greater than the number of pole electrodes of the second multipolar structure.

[0160] 32. The method of any of clauses 28-31, further comprising placing a plurality of multipolar structures in one or more layers.

[0161] 33. The method of clause 32, wherein a multipolar structure in a first layer of the one or more layers is aligned with a multipolar structure in a second layer of the one or more layers.

[0162] 34. A method according to any of clauses 28 to 33, further comprising grouping subsets of the multi-pole structures to share a single driver, wherein the subsets of the multi-pole structures:

[0163] have the same number of polar electrodes, and

[0164] Equal or substantially equal in radial offset and orientation angle.

[0165] 35. A method according to any of clauses 32-34, further comprising grouping a subset of the multi-pole structures in a first layer of the one or more layers into a shared first driver, wherein the subset of the multi-pole structures in the first layer:

[0166] have the same number of polar electrodes, and

[0167] Equal or substantially equal in radial offset and orientation angle.

[0168] 36. The method according to any of clauses 32-35 further comprises grouping a subset of the multipolar structures in a second layer of one or more layers into a shared second drive, wherein the subset of the multipolar structures in the second layer: have the same number of pole electrodes and are equal or substantially equal in radial offset and orientation angles.

[0169] 37. A microstructure deflector array comprising a plurality of multipole structures, each multipole structure comprising a plurality of polar electrodes, the array comprising:

[0170] a first group of multipole structures of the plurality of multipole structures, the first group of multipole structures having a first set of radial offsets from a central axis of the array, wherein each multipole structure of the first group includes a same number of corresponding polar electrodes; and

[0171] a second group of multipole structures of the plurality of multipole structures, the second group of multipole structures having a second set of radial offsets from a central axis of the array, wherein each multipole structure of the second group includes the same number of corresponding polar electrodes,

[0172] Wherein the multipolar structures in the first group include a greater number of polar electrodes than the multipolar structures in the second group, and wherein each of the first group and the second group includes one or more multipolar structures.

[0173] 38. An array according to clause 37, wherein a minimum value of the radial offset of the first set of radial offsets is higher than a maximum value of the radial offset of the second set of radial offsets.

[0174] 39. An array according to clause 37, wherein the plurality of multipole structures are configured to deflect the plurality of charged particle beams substantially simultaneously.

[0175] 40. The array of clause 39, wherein the first group of multipolar structures comprises:

[0176] A first subset of the multi-pole structures is electrically connected to and driven by the first driver, wherein radial offsets and orientation angles of the first subset of the multi-pole structures are substantially equal.

[0177] 41. The array of clause 40, wherein the second set of multipolar structures comprises:

[0178] A second subset of the multi-pole structures is electrically connected to and driven by the second driver, wherein the radial offset and orientation angles of the second subset of the multi-pole structures are equal or substantially equal.

[0179] 42. An array according to claim 41, wherein one of the first drive and the second drive is configured to enable the corresponding multipole structure to deflect multiple charged particle beams in a multi-beam device, and wherein the multiple multipole structures are also configured as imaging elements or pre-bent micro-deflectors in the multi-beam device.

[0180] 43. The array of clause 37, wherein the multipole structures in the first group have an inner diameter that is greater than the inner diameter of the multipole structures in the second group.

[0181] 44. An array according to clause 39, wherein the first group and the second group are arranged in a first layer of the array, and wherein the array also includes a second layer, the second layer includes a third group of multipolar structures, the third group of multipolar structures having a third radial offset from the central axis of the array.

[0182] 45. The array of clause 44, wherein the third radial offset is different from the first set of radial offsets or the second set of radial offsets.

[0183] 46. ​​An array according to clause 45, wherein the number of polar electrodes of the third multipolar structure is different from or equal to the number of polar electrodes of the multipolar structures in the first group of multipolar structures.

[0184] 47. The array of clause 45, wherein one of the plurality of charged particle beams is deflected by a multipole structure in the first layer and another of the plurality of charged particle beams is deflected by a multipole structure in the second layer.

[0185] 48. An array according to clause 45, wherein one of the plurality of charged particle beams is deflected by a multipole structure in a first layer and a multipole structure in a second layer connected in series, and the multipole structures in the first layer and the multipole structures in the second layer are aligned with each other.

[0186] 49. The array of clause 45, wherein:

[0187] a first beam of the plurality of charged particle beams is deflected by a multipole structure in the first layer and is not deflected by any multipole structure in the second layer,

[0188] a second beam of the plurality of charged particle beams is deflected by the multipole structure in the second layer and is not deflected by any multipole structure in the second layer, and

[0189] A third beam of the plurality of charged particle beams is deflected by the multipole structure in the first layer and the multipole structure in the second layer in series.

[0190] 50. A source conversion unit in a charged particle beam system, wherein the source conversion unit comprises a microstructure deflector array, the microstructure deflector array comprises a plurality of multipole structures, each of the multipole structures comprises a plurality of pole electrodes, the array comprises:

[0191] a first group of multipole structures of the plurality of multipole structures, the first group of multipole structures having a first set of radial offsets from a central axis of the array, wherein each multipole structure in the first group includes a same number of pole electrodes; and

[0192] a second group of multipole structures of the plurality of multipole structures, the second group of multipole structures having a second set of radial offsets from a central axis of the array, wherein each multipole structure in the second group comprises the same number of pole electrodes,

[0193] wherein the first set of radial offsets is different from the second set of radial offsets, wherein the multipole structures in the first group include a greater number of pole electrodes than the multipole structures in the second group, and wherein each of the first and second groups includes one or more multipole structures.

[0194] 51. A source conversion unit according to clause 50, wherein the first group and the second group are arranged in a first layer of an array, the array also comprising a second layer, the second layer comprising a third group of multipole structures, the third group of multipole structures having a third radial offset from the central axis of the array.

[0195] 52. An array according to any of clauses 6 to 10, wherein the drivers of the first driver and the second driver are configured to enable the corresponding multipole structure to be used as an imaging element or a pre-bent micro-deflector in a multi-beam device to deflect multiple charged particle beams.

[0196] 53. The array of clause 52, wherein the drivers of the first driver and the second driver are configured comprises: all of the first driver and the second driver are configured.

[0197] Although the present invention has been described in conjunction with various embodiments, other embodiments of the present invention will be apparent to those skilled in the art in view of the specification and practice of the invention disclosed herein. The specification and examples are to be considered exemplary only, with the true scope and spirit of the present invention being indicated by the appended claims.

[0198] The above description is intended to be illustrative, rather than limiting. It will therefore be apparent to one skilled in the art that modifications described may be made without departing from the scope of the claims.

Claims

1. A microstructure deflector array, comprising a plurality of multipole structures, each multipole structure comprising a plurality of pole electrodes, the array comprising: a first multipole structure of the plurality of multipole structures, the first multipole structure having a first radial offset from a central axis of the array; as well as a second multipole structure of the plurality of multipole structures, the second multipole structure having a second radial offset from the central axis of the array, The first radial offset is greater than the second radial offset, and the first multipole structure includes a greater number of pole electrodes than the second multipole structure. 2 . The array of claim 1 , wherein the first multipole structure comprises a greater number of pole electrodes than the second multipole structure to reduce deflection aberrations when the plurality of multipole structures deflect a plurality of charged particle beams.

3. An array according to any one of claims 1 and 2, wherein: The plurality of electrodes of the first multi-pole structure are electrically connected and driven by a first driver, and The plurality of electrodes of the second multi-pole structure are electrically connected and driven by a second driver.

4. The array of claim 3, wherein the first driver and the second driver are configured to enable the first multipole structure and the second multipole structure to be used as imaging elements or pre-bent micro-deflectors in a multi-beam device to deflect multiple charged particle beams.

5. The array of any one of claims 1-4, wherein the first multipole structure has an inner diameter that is larger than an inner diameter of the second multipole structure.

6. A microstructure deflector array, comprising a plurality of multipole structures, each multipole structure comprising a plurality of pole electrodes, the array comprising: a first group of multipole structures of the plurality of multipole structures, the first group of multipole structures having a first set of radial offsets from a central axis of the array, wherein each multipole structure of the first group includes a same number of corresponding polar electrodes; as well as a second group of multipole structures of the plurality of multipole structures, the second group of multipole structures having a second set of radial offsets from the central axis of the array, wherein each multipole structure in the second group includes the same number of corresponding polar electrodes, wherein a minimum value of the radial offset in the first set of radial offsets is higher than a maximum value of the radial offset in the second set of radial offsets, and wherein the multipole structures in the first group include a greater number of pole electrodes than the multipole structures in the second group.

7. The array of claim 6, wherein the multipole structures in the first group include a greater number of pole electrodes than the multipole structures in the second group to reduce deflection aberrations when the plurality of multipole structures deflect a plurality of charged particle beams.

8. An array according to any one of claims 6 and 7, wherein the first group or the second group may comprise only one multipole structure.

9. The array of any one of claims 6-8, wherein the first group of multipole structures in the plurality of multipole structures comprises: A first subset of multi-pole structures is electrically connected and driven by a first driver, wherein the radial offset and orientation angles of the first subset of multi-pole structures are equal or substantially equal.

10. The array of any one of claims 6 to 9, wherein the second group of multipole structures in the plurality of multipole structures comprises: A second subset of multi-pole structures is electrically connected and driven by a second driver, wherein the radial offset and orientation angles of the second subset of multi-pole structures are equal or substantially equal.

11. An array according to any one of claims 6-10, wherein at least one of the first driver and the second driver is configured to enable the corresponding multipole structure to be used as an imaging element or a pre-bent micro-deflector in a multi-beam device to deflect multiple charged particle beams.

12. The array according to any one of claims 6-11, wherein the inner diameter of one multipole structure of the first group is larger than the inner diameter of one multipole structure of the second group.

13. A microstructure deflector array, comprising a plurality of multipole structures configured to deflect a plurality of charged particle beams, each multipole structure comprising a plurality of pole electrodes, the array comprising: a first layer of multipole structures of the plurality of multipole structures, the first layer comprising a first multipole structure having a first radial offset from a central axis of the array and a second multipole structure having a second radial offset from the central axis of the array, wherein the first radial offset is greater than the second radial offset and the first multipole structure comprises a greater number of pole electrodes than the second multipole structure; as well as A second layer of multipole structures in the plurality of multipole structures, the second layer comprising a third multipole structure having a third radial offset from the central axis of the array.

14. The array of claim 13, wherein the first multipole structure comprises a greater number of pole electrodes than the second multipole structure to reduce deflection aberrations of the corresponding charged particle beam.

15. An array according to any one of claims 13 and 14, wherein the third radial offset is less than the first radial offset.

16. The array of claim 15, wherein the third radial offset is greater than the second radial offset.

17. The array according to any one of claims 13-16, wherein the number of polar electrodes of the third multipolar structure is greater than or equal to the number of polar electrodes of the second multipolar structure.

18. The array according to any one of claims 13-16, wherein the number of polar electrodes of the third multipolar structure is less than or equal to the number of polar electrodes of the first multipolar structure.

19. The array of any one of claims 13, 14, 16 and 17, wherein the third multipolar structure comprises a greater or equal number of polar electrodes than the first multipolar structure.

20. The array of any one of claims 13-19, wherein one of the plurality of charged particle beams is deflected by a multipole structure in the first layer, and another of the plurality of charged particle beams is deflected by a multipole structure in the second layer.

21. An array according to any one of claims 13-19, wherein one of the multiple charged particle beams is deflected by a multipole structure in the first layer and a multipole structure in the second layer connected in series, and the multipole structure in the first layer and the multipole structure in the second layer are aligned with each other.

22. An array according to any one of claims 13 to 19, wherein: a first beam of the plurality of charged particle beams is deflected by a multipole structure in the first layer, A second beam of the plurality of charged particle beams is deflected by a multipole structure in the second layer, and A third beam of the plurality of charged particle beams is deflected by a multipole structure in the first layer and a multipole structure in the second layer connected in series.

23. The array of any one of claims 13-22, wherein each multipole structure of the plurality of multipole structures is placed inside an electrically shielded cavity to be electrically shielded from other multipole structures.

24. The array of any one of claims 13-23, wherein an inner diameter of a first multipole structure in the first layer is greater than an inner diameter of a second multipole structure in the first layer.

25. The array of any one of claims 13-24, wherein two or more of the multipolar structures in the first layer: With the same number of electrodes, are equal or substantially equal in radial offset and orientation angle, and The first driver is electrically connected to and driven by the first driver.

26. The array of any one of claims 13-25, wherein two or more of the multipolar structures in the second layer: With the same number of electrodes, are equal or substantially equal in radial offset and orientation angle, and Electrically connected to and driven by a second driver.

27. A source conversion unit in a charged particle beam system, comprising an array according to any one of claims 13-26.

28. A method of manufacturing a microstructure deflector array comprising a plurality of multipole structures, each multipole structure comprising a plurality of pole electrodes, the method comprising: forming the first multipole structure to have a first radial offset from a central axis of the array; as well as The second multipole structure is formed to have a second radial offset from the central axis of the array, wherein the first radial offset is greater than the second radial offset and the first multipole structure has a different number of pole electrodes than the second multipole structure.

29. The method of claim 28, further comprising selecting a number of pole electrodes of the first multipole structure and a number of pole electrodes of the second multipole structure based on aberration characteristics of the first multipole structure and the second multipole structure.

30. The method of claim 29, wherein selecting the number of polar electrodes of the first multipole structure and the number of polar electrodes of the second multipole structure comprises selecting the corresponding number of polar electrodes to reduce high-order components of their electric fields.

31. The method according to any one of claims 28-30, wherein the number of polar electrodes of the first multipolar structure is greater than the number of polar electrodes of the second multipolar structure.

32. The method of any one of claims 28-31, further comprising placing the plurality of multipolar structures in one or more layers.

33. The method of claim 32, wherein a multipole structure in a first layer of the one or more layers is aligned with a multipole structure in a second layer of the one or more layers.

34. The method of any of claims 28-33, further comprising grouping subsets of multi-pole structures to share one driver, wherein the subsets of multi-pole structures: have the same number of polar electrodes, and Equal or substantially equal in radial offset and orientation angle.

35. The method of any of claims 32-34, further comprising grouping a subset of multi-pole structures in a first layer of the one or more layers into a shared first driver, wherein the subset of multi-pole structures in the first layer: have the same number of polar electrodes, and Equal or substantially equal in radial offset and orientation angle.

36. The method according to any one of claims 32-35 further includes grouping a subset of the multipolar structures in the second layer of one or more layers into a shared second driver, wherein the subset of the multipolar structures in the second layer: have the same number of pole electrodes and are equal or substantially equal in radial offset and orientation angles.

37. A microstructure deflector array comprising a plurality of multipole structures, each multipole structure comprising a plurality of pole electrodes, the array comprising: a first group of multipole structures of the plurality of multipole structures, the first group of multipole structures having a first set of radial offsets from a central axis of the array, wherein each multipole structure of the first group includes a same number of corresponding polar electrodes; as well as a second group of multipole structures of the plurality of multipole structures, the second group of multipole structures having a second set of radial offsets from a central axis of the array, wherein each multipole structure of the second group includes the same number of corresponding polar electrodes, Wherein the multipolar structures in the first group include a greater number of polar electrodes than the multipolar structures in the second group, and wherein each of the first group and the second group includes one or more multipolar structures.

38. An array according to claim 37, wherein a minimum value of the radial offset of the first set of radial offsets is higher than a maximum value of the radial offset of the second set of radial offsets.

39. The array of claim 37, wherein the plurality of multipole structures are configured to deflect a plurality of charged particle beams substantially simultaneously.

40. The array of claim 39, wherein the first set of multipolar structures comprises: A first subset of multi-pole structures is electrically connected to and driven by a first driver, wherein the radial offset and orientation angles of the first subset of multi-pole structures are substantially equal.

41. The array of claim 40, wherein the second set of multipolar structures comprises: A second subset of multi-pole structures is electrically connected to and driven by a second driver, wherein the radial offsets and orientation angles of the second subset of multi-pole structures are equal or substantially equal.

42. An array according to claim 41, wherein one of the first driver and the second driver is configured to enable a corresponding multipole structure to deflect the multiple charged particle beams in a multi-beam device, and wherein the multiple multipole structures are also configured as imaging elements or pre-bent micro-deflectors in the multi-beam device.

43. The array of claim 37, wherein the multipole structures in the first group have an inner diameter that is greater than the inner diameter of the multipole structures in the second group.

44. An array according to claim 39, wherein the first group and the second group are arranged in a first layer of the array, and wherein the array also includes a second layer, the second layer includes a third group of multipolar structures, and the third group of multipolar structures has a third radial offset from the central axis of the array.

45. An array as in claim 44, wherein the third radial offset is different from the first set of radial offsets or the second set of radial offsets.

46. ​​The array of claim 45, wherein the number of polar electrodes of the third multipolar structure is different from or equal to the number of polar electrodes of the multipolar structures in the first group of multipolar structures.

47. The array of claim 45, wherein one of the plurality of charged particle beams is deflected by a multipole structure in the first layer, and another of the plurality of charged particle beams is deflected by a multipole structure in the second layer.

48. An array according to claim 45, wherein one charged particle beam among the plurality of charged particle beams is deflected by a multipole structure in the first layer and a multipole structure in the second layer connected in series, and the multipole structure in the first layer and the multipole structure in the second layer are aligned with each other.

49. The array of claim 45, wherein: a first beam of the plurality of charged particle beams is deflected by a multipole structure in the first layer and is not deflected by any multipole structure in the second layer, a second beam of the plurality of charged particle beams is deflected by a multipole structure in the second layer and is not deflected by any multipole structure in the first layer, and A third beam of the plurality of charged particle beams is deflected by a multipole structure in the first layer and a multipole structure in the second layer connected in series.

50. A source conversion unit in a charged particle beam system, wherein the source conversion unit comprises a microstructure deflector array, the microstructure deflector array comprises a plurality of multipole structures, each of the multipole structures comprises a plurality of pole electrodes, the array comprises: a first group of multipole structures of the plurality of multipole structures, the first group of multipole structures having a first set of radial offsets from a central axis of the array, wherein each multipole structure in the first group includes a same number of pole electrodes; as well as a second group of multipole structures of the plurality of multipole structures, the second group of multipole structures having a second set of radial offsets from the central axis of the array, wherein each multipole structure in the second group includes the same number of pole electrodes, wherein the first set of radial offsets is different from the second set of radial offsets, wherein the multipole structures in the first group include a greater number of pole electrodes than the multipole structures in the second group, and wherein each of the first group and the second group includes one or more multipole structures.

51. A source conversion unit according to claim 50, wherein the first group and the second group are arranged in a first layer of the array, the array also including a second layer, the second layer including a third group of multipole structures, and the third group of multipole structures has a third radial offset from the central axis of the array.

52. An array according to any one of claims 6-10, wherein the drivers in the first driver and the second driver are configured so that the corresponding multipole structures can be used as imaging elements or pre-bent micro-deflectors in a multi-beam device to deflect multiple charged particle beams.

53. The array of claim 52, wherein the drivers in the first driver and the second driver are configured to include: All of the first driver and the second driver are configured.

Images